package com.qdairlines.shiro.realm;

import java.util.HashSet;
import java.util.List;

import javax.annotation.PostConstruct;

import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.UsernamePasswordToken;
import org.apache.shiro.authz.AuthorizationException;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.session.Session;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.subject.Subject;
import org.springframework.beans.factory.annotation.Autowired;

import com.qdairlines.entity.user.User;
import com.qdairlines.service.user.PermissionService;
import com.qdairlines.service.user.RoleService;
import com.qdairlines.service.user.UserService;

public class MyRealm extends AuthorizingRealm {

    @Autowired
    private UserService userService;
    @Autowired
    private RoleService roleService;
    @Autowired
    private PermissionService permissionService;

    /**
     * 为当前登录的Subject授予角色和权限
     * 
     * @see 经测试:本例中该方法的调用时机为需授权资源被访问时
     * @see 经测试:并且每次访问需授权资源时都会执行该方法中的逻辑,这表明本例中默认并未启用AuthorizationCache
     * @see 个人感觉若使用了Spring3
     *      .1开始提供的ConcurrentMapCache支持,则可灵活决定是否启用AuthorizationCache
     * @see 比如说这里从数据库获取权限信息时,先去访问Spring3.1提供的缓存,而不使用Shior提供的AuthorizationCache
     */
    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
    							
	// 获取当前登录的用户名
	String currentUsername = (String) super.getAvailablePrincipal(principals);
	
		User user = userService.getUserByUserName(currentUsername);
		SimpleAuthorizationInfo simpleAuthorInfo = new SimpleAuthorizationInfo();
		if (null != user) {
		    // 为当前用户设置角色和权限
			List<String> userRoleNameList = roleService.listRoleCodeByWorkcode(user.getWorkcode());
			List<String> userPermissionNameList =  permissionService.listPermissionCodeByWorkcode(user.getWorkcode());
		    simpleAuthorInfo.setRoles(new HashSet<String>(userRoleNameList));
		    simpleAuthorInfo.setStringPermissions(new HashSet<String>(userPermissionNameList));
		} else {
		    throw new AuthorizationException();
		}
	
		return simpleAuthorInfo;
    }

    /**
     * 验证当前登录的Subject
     * 
     * @see 经测试:本例中该方法的调用时机为LoginController.login()方法中执行Subject.login()时
     */
    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) throws AuthenticationException {
		// 获取基于用户名和密码的令牌
		// 实际上这个authcToken是从LoginController里面currentUser.login(token)传过来的
		// 两个token的引用都是一样的
		UsernamePasswordToken token = (UsernamePasswordToken) authcToken;
		System.out.println("Subject token" + ReflectionToStringBuilder.toString(token, ToStringStyle.MULTI_LINE_STYLE));
		User user = userService.getUserByUserName(token.getUsername());
		if (null != user) {
		    AuthenticationInfo authcInfo = new SimpleAuthenticationInfo(user.getUserName(), user.getPassword(), user.getUserRealName());
		    this.setSession("currentUser", user);
		    return authcInfo;
		} else {
		    return null;
		}

    }
    
    @PostConstruct  
    public void initCredentialsMatcher() {  
	//该句作用是重写shiro的密码验证，让shiro用我自己的验证  
        setCredentialsMatcher(new MyCredentialsMatcher());
    }

    /**
	 *
	 */
    private void setSession(Object key, Object value) {
	Subject currentUser = SecurityUtils.getSubject();
		if (null != currentUser) {
		    Session session = currentUser.getSession();
		    System.out.println("Session超时[" + session.getTimeout() + "]");
		    if (null != session) {
			session.setAttribute(key, value);
		    }
		}
    }
}
